• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

mopar electronic ignition failure

wild bill

Well-Known Member
Local time
5:29 AM
Joined
May 11, 2015
Messages
82
Reaction score
11
Location
alma michigan
Hi folks. This is wild bill again. did want to report a systems failure in my 1969 Road Runner restoration. I installed a mopar ignition box along with an electronic distributor. I used the old style voltage regulator and alternator (50 amp). I also installed a stereo amp (600 watts) along with a capacitor. What happened is the capacitor sucked so much power it caused my volt regulator to fail (I believe anyway). then my alternator fried. the car was running when I shut it off. Next, I replaced the volt regulator and alt (60 amp), and connected the battery. during this procedure I then heard sparking noises coming from the ign box. Yep. I fried the ign box to. Question: is the mopar (MSD) ignition box compatible with the mechanical volt regulator? or should I switch to an electronic volt reg? I plan to add fuses in the ign box power line when it comes back (4 wks) from repair. Any suggestions comments?
 
I "think" your '69 voltage regulator is the same as my '70 voltage regulator. My car came with points just like yours. I've run both the Chrysler ignition box (silver, orange & black boxes) + a MSD 6A (still in there) without changing the voltage regulator. Using the MSD box, I removed the ballast resistor (ignition voltage is not stepped down) & the instructions for the MSD box said to wire it directly to the + of the battery, no fuses, no nothin'...direct, which is what I've done successfully for 20 yrs. using the MSD-6A
 
I cannot answer your question, but I did have a mechanical voltage regulator that was overcharging. I did not notice it until I installed a gauge cluster under the dash. It was pegged at 16v so no telling how much it was taking. I replaced the VR with an electronic Wells VR. Not long after, my ECU failed and I attribute it to the overcharging. I replaced it and have had no ignition problem since.
 
I cannot answer your question, but I did have a mechanical voltage regulator that was overcharging. I did not notice it until I installed a gauge cluster under the dash. It was pegged at 16v so no telling how much it was taking. I replaced the VR with an electronic Wells VR. Not long after, my ECU failed and I attribute it to the overcharging. I replaced it and have had no ignition problem since.
 
Thanks Ranger. I did want to add that before I attempted to "reboot" system I disconnected the capacitor from the system, and checked all wires to make sure they were not damaged (none were). I am curious if your ECU failed after you put new electronic volt regulator in? I agree ECU failure due to "spike" in volts (amps). I plan to attempt to remedy by placing a fuse in the ECU power (red,12 guage) wire. I am worried that when i put repaired ECU in it will fail again. But I believe i found the issue.
 
I "think" your '69 voltage regulator is the same as my '70 voltage regulator. My car came with points just like yours. I've run both the Chrysler ignition box (silver, orange & black boxes) + a MSD 6A (still in there) without changing the voltage regulator. Using the MSD box, I removed the ballast resistor (ignition voltage is not stepped down) & the instructions for the MSD box said to wire it directly to the + of the battery, no fuses, no nothin'...direct, which is what I've done successfully for 20 yrs. using the MSD-6A

The '69 & '70 regulars are not the same. The '70 electronic is totally different from the earlier pieces. Follow the MSD directions.
 
I "think" your '69 voltage regulator is the same as my '70 voltage regulator. My car came with points just like yours. I've run both the Chrysler ignition box (silver, orange & black boxes) + a MSD 6A (still in there) without changing the voltage regulator. Using the MSD box, I removed the ballast resistor (ignition voltage is not stepped down) & the instructions for the MSD box said to wire it directly to the + of the battery, no fuses, no nothin'...direct, which is what I've done successfully for 20 yrs. using the MSD-6A
Ok thanks Purplebeeper. I too had my RR running with a "mech" volt regular with the Mopar (MSD) box. It ran good for a while. I think the stereo capacitor i installed was the initial problem so that comes out. I guess I try again. Thanks for your comment. I am wondering if your volt reg on your 70 is an "electronic? the 69s came with a "mechanical" type.
 
i switch all the cars i do to one wire 100 amp alt.only reason to go the other route is to keep it stock.no muss,no fuss,powers any electronics you want to slap in there.
 
Why is it everybody does this? I don't know! Read this good and go get yourself the NEW style Reg and wire it up as follows. Good Luck
READ- http://www.imperialclub.com/Repair/Electrical/charging.htm
69a100. wow! great article. it answers my question. I SHOULD switch from the pre 69 "mechanical" voltage regulator to the post 69 transistoized VR because I went from a points system to electronic ignition. Thank you for the direction!
 
It did, but I suspect that the damage was cumulative and had already been done.

Ranger 16. YES! thats what i was thinking too! damage was done, the unit was on the edge of the cliff and when i attempted to put it under a load (after repairs) it went over the cliff. Kool!
 
i switch all the cars i do to one wire 100 amp alt.only reason to go the other route is to keep it stock.no muss,no fuss,powers any electronics you want to slap in there.
Yes I was thinking the same thing. Just go to one wire alt would solve problem.
 
Yes I was thinking the same thing. Just go to one wire alt would solve problem.
ok thanks everyone. I think this what i learned options: (1). go all stock for 69. mech volt reg, external 50/60 amp alternator, dont stress system out by adding too many electronic gizmos, use MSD type box at your own risk! (2). hybrid sysstem use external amp alternator, ELECTRONIC voltage regulator, MSD type box prolly should work better (see article 69a100 referenced). (3). one wire modern alternator, and elect problems solved. Question is what is ur build philosophy? original look has its costs. go all modern and u loose some of the orginal look. can install original parts , but make them dummy (non-functional) is the way i think iam headed. Thank you all for your input. I never wanted to know this much!!!
 
ok thanks everyone. I think this what i learned options: (1). go all stock for 69. mech volt reg, external 50/60 amp alternator, dont stress system out by adding too many electronic gizmos, use MSD type box at your own risk! (2). hybrid sysstem use external amp alternator, ELECTRONIC voltage regulator, MSD type box prolly should work better (see article 69a100 referenced). (3). one wire modern alternator, and elect problems solved. Question is what is ur build philosophy? original look has its costs. go all modern and u loose some of the orginal look. can install original parts , but make them dummy (non-functional) is the way i think iam headed. Thank you all for your input. I never wanted to know this much!!!
EPILOGUE: from Wild Bill. I installed one wire power master (Part No. PWM 75191) 90 amp, square back design internally regulated. Looks close to original, but not the same. I sent the MSD box in for repairs. MSD said box is fine. checked coil, and it was fine. MSD said look for signal from disbutor. I found that the wires (2) coming from the dist to the MSD box had come loose from the but connectors. (Solder next time). Thus no signal from dist to box!!!. Repaired and continued. I read MSD instructions again (7 or 8 times really). INst said you do NOT NEED TO BY PASS the balast resistor. I thus put in function bal resistor and continued. I ck for current (at least 8.5 volts) needed to trigger the MSD box. I had this. Ck for current at balast resistor (both sides) had it. (12 + volts with ign to on
 
EPILOGUE: from Wild Bill. I installed one wire power master (Part No. PWM 75191) 90 amp, square back design internally regulated. Looks close to original, but not the same. I sent the MSD box in for repairs. MSD said box is fine. checked coil, and it was fine. MSD said look for signal from disbutor. I found that the wires (2) coming from the dist to the MSD box had come loose from the but connectors. (Solder next time). Thus no signal from dist to box!!!. Repaired and continued. I read MSD instructions again (7 or 8 times really). INst said you do NOT NEED TO BY PASS the balast resistor. I thus put in function bal resistor and continued. I ck for current (at least 8.5 volts) needed to trigger the MSD box. I had this. Ck for current at balast resistor (both sides) had it. (12 + volts with ign to on
position. Good. Car started and ran fine. I reinstalled cable to sterio amp. Good there no issues. I had another problem with wet pully belt but fixed that with help from Forum folks (THANK YOU!!). Looks line one wire alt is doable, and can be used in conjunction with MSD Capac Box and electronic ign. I thought it wise to kept balast resistor in system but did not use the external volt reg since the PM has its own internal reg. U can bypass the bal resistor but it is not necessary per Instruction by MSD. Car starts now and runs fine. Thanks everyone 4 your help!!!
 
Hi folks. This is wild bill again. did want to report a systems failure in my 1969 Road Runner restoration. I installed a mopar ignition box along with an electronic distributor. I used the old style voltage regulator and alternator (50 amp). I also installed a stereo amp (600 watts) along with a capacitor. What happened is the capacitor sucked so much power it caused my volt regulator to fail (I believe anyway). then my alternator fried. the car was running when I shut it off. Next, I replaced the volt regulator and alt (60 amp), and connected the battery. during this procedure I then heard sparking noises coming from the ign box. Yep. I fried the ign box to. Question: is the mopar (MSD) ignition box compatible with the mechanical volt regulator? or should I switch to an electronic volt reg? I plan to add fuses in the ign box power line when it comes back (4 wks) from repair. Any suggestions comments?

There are many instances where an electronic distributor or capacitive discharge style distributor are installed and a complete failure of the entire system for ignition fails. It is near impossible to run electronic distributors with mechanical regulators because of the voltage variance these units create. It is highly recommended that electronic distributors have the voltage regulator to be of the electronic type as well. Even better is to install an alternator which incorporates the voltage regulator. These units respond much quicker to voltage/amperage changes and are usually of higher amperage output.
"One wire" alternators can also exhibit huge output variances depending on the rpm's required to get a consistently steady output. You really need to check with the manufacturers as to their specs at varying loads and response. I've been of the belief that if "one wire" was so great, why do we not see them on all newer cars. Simple, newer vehicles have alternators with a sensing circuit to ensure they don't over/under charge and the diodes switch in and out to remove spikes in output that can damage sensitive circuits and high loads. A Ford 3G is one of the best at this and will mount directly to most Mopar engines and has the capability of putting out up to 130 amps. With a VOM meter you will quickly see how smooth these units are on load changes while maintaining a constant voltage output. GM and Chrysler also make remarkable alternators with fast load/voltage switching. I believe you can not get better charging or output linearity than with a sensing alternator and I'm sure Chrysler, GM and Ford would agree with me. So if your going electronic, make sure to give serious consideration to the type of charging system you have. That's why MSD's control boxes wire directly to battery positive - they cannot handle voltage spikes and neither can electronic distributors.
 
Back
Top